As the artificial kidney perfusion fluid for bicarbonate dialysis (hereinafter referred to briefly as bicarbonate dialyzate), an aqueous system prepared by blending two artificial kidney perfusion components, i.e. the so-called Component A comprising electrolytes, namely sodium chloride, potassium chloride, calcium chloride, magnesium chloride and sodium acetate, optionally supplemented with glucose, and the so-called Component B comprising a powder or an aqueous solution of sodium bicarbonate is generally employed.
For reference, the amounts of said respective ingredients contained in each 10 liters of the bicarbonate dialyzate in common use are shown in Table 1.
TABLE 1 ______________________________________ &lt;Component A&gt; Sodium chloride 1943.1.about.2238.0 g Potassium chloride 26.1.about.104.4 g Calcium chloride 25.7.about.102.9 g Magnesium chloride 17.8.about.71.2 g Sodium acetate 57.42.about.344.5 g Glucose 0.about.700 g &lt;Component B&gt; Sodium bicarbonate 588.1.about.928 g ______________________________________
Regarding Component B, both a solution form and a powdery form have been developed for selective use. As to Component A, which is a mixture of several ingredients, it is difficult to provide a powder of uniform composition. At the present time, therefore, an aqueous solution is manufactured and packaged in polyethylene bottles of about 10 l capacity in the factory and shipped to hospitals and dialysis centers. However, because Component A in the solution form is substantial in weight and volume, it is not satisfactory from the standpoint of shipping cost and storage space available in hospitals and so on. Moreover, it is undesirable in view of the problems associated with the disposal of polyethylene bottles after use.
As the pulverization technology for Component A, the dry granulation method comprising mix-pulverizing the electrolyte compounds and the wet granulation method comprising granulating and drying a slurry of the electrolyte compounds are known. However, these physical pulverizing and granulating methods are disadvantageous in that the charge tends to be contaminated with foreign matter due to friction with the equipment in the course of pulverization and granulation.
Moreover, the powder obtained by the known dry granulation method has the drawback that since the respective electrolyte compounds vary in hardness and some of them are readily pulverized while others are not and, hence, the former can be more readily granulated than the latter, a large difference in composition tends to occur between the recovered granulation and the powdery residue. In other words, the ratio of the respective electrolyte compounds in the charge formulation is sometimes at odds with their ratio in the final granulation and it happens at times that some electrolyte compounds must be supplementally added after granulation to correct for deficiencies.
As a means for overcoming this disadvantage, there has been proposed a method which comprises comminuting the respective electrolyte compounds into fine particles to increase the hardness of the resultant granulation and reduce the amount of powdery residues. However, it takes a time-consuming procedure to finely divide electrolyte compounds and in order to reduce the amount of powdery residues, a repeated granulation cycle is required but the practice increases the chance for the electrolyte compounds to be contaminated with foreign matter arising from frictional attrition of the pulverizing and granulating hardware.
As to the wet-granulation method, coagulation on drying tends to produce blocks which have to be crushed prior to final size selection so that the production process is complicated and unsuited for mass production.